1. Field of the Invention
This invention relates to improvements in stays designed for use in the adjustable mounting of windows or the like.
2. Prior Art
It is already known to provide a window stay having a window frame mounting plate, two arms of different length each pivoted at one end to the window mounting plate, a window sash mounting plate pivoted to outer ends of the two arms, each pivoted joint being a wear-resistant friction type joint. Such a window stay is described in U.S. Pat. No. 3,497,909.
This type of window stay has been most satisfactory in the mounting of windows with one of the many advantages being that it provides, when open, a clear space between the top of the sash and the window frame so that the window may be cleaned. In addition the friction type joints permit the window to be opened to any one of a number of positions between closed and fully open and firmly retains the window in that position so that the required amount of ventilation can be obtained.
In some countries new standards have or are being enforced which in part are concerned with safety requirements for the cleaning of windows. The requirements limit the distance a window cleaner may be required to reach from inside the building to clean the outside of windows. Additionally some standards are now limiting the force which a person must apply to open so called "frictional restrained" windows. According to these standards the maximum applied force must not exceed 80 Newtons. Still further in some countries window stays must be of a design which permit controlled opening of windows to large degrees of opening so that adequate ventilation can be achieved.
A further type of known window stay comprises a frame mounting plate, a sliding shoe incorporated with the mounting plate, a sash mounting plate pivoted at one end to the shoe and pivotally coupled to the frameplate by an arm. This type of stay suffers from the shoe not having a smooth and non-jamming movement along the frameplate. In addition this type of stay cannot, because of its construction, move the head of the sash directly out and back from the frame for effective weatherproofing and requires a more complicated window construction.
It is an object of the present invention to provide a window stay for adjustable mounting of a window sash on a window frame which is easy to operate, is not prone to jamming and allows the sash to be reversed in relation to the frame for cleaning of the window pane.